# US 2014/0191967 A1 · Electronic device for recognizing asynchronous digital pen and recognizing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191967 A1 - Document ID: US20140191967A1 - Status: Published application - Kind: A1 - Application number: 14/096,577 - Filed: 2013-12-04 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Bong-Jae RHEE - Web page: https://patentgrep.com/patent/US20140191967A1 ## CPC - G06F 3/03545: {Pens or stylus} - G06F 3/043: using propagating acoustic waves - G06F 3/0433: {in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An electronic device for receiving an input by a digital pen having a waveform generation means is provided. The electronic device includes at least three reception sensors and a processor. The at least three reception sensors are installed in the electronic device at positions that are separated from one another, and are configured to receive a waveform generated by the waveform generator of the digital pen. The processor is configured to calculate an input coordinate of the digital pen using a difference of velocities and reception times of the waveform received by the at least three reception sensors. ## Claims ### Claim 1 An electronic device comprising a digital pen, the electronic device comprising: at least three reception sensors installed in the electronic device at positions that are separated from one another, the at least three reception sensors configured to receive a waveform generated by a waveform generator of the digital pen; and a processor configured to calculate an input coordinate of the digital pen using a difference of velocities and reception times of the waveform received by the at least three reception sensors. ### Claim 2 (depends on 1) The electronic device of claim 1, wherein at least one of the at least three reception sensors is not disposed on a line between at least two other of the at least three reception sensors. ### Claim 3 (depends on 1) The electronic device of claim 1, wherein the reception sensors are disposed in a region of the electronic device other than a display region of a display unit provided to the electronic device. ### Claim 4 (depends on 1) The electronic device of claim 1, wherein the waveform generator comprises an ultrasonic wave generating unit, and the at least three reception sensors comprise ultrasonic reception sensors. ### Claim 5 (depends on 1) The electronic device of claim 1, wherein the waveform generator comprises a vibration generating unit, and the at least three reception sensors comprise vibration reception sensors. ### Claim 6 (depends on 1) The electronic device of claim 1, wherein the waveform is generated in a form of a pulse or in a form of a modulated continuous wave. ### Claim 7 (depends on 1) The electronic device of claim 1, wherein a 2-Dimensional (2D) input coordinate of the digital pen is calculated using a difference between transfer times of at least two cases of waveforms received by the at least three reception sensors. ### Claim 8 (depends on 7) The electronic device of claim 7, wherein the input coordinate of the digital pen is calculated using non-linear simultaneous equations comprising: 1) d1−d2=[(x−x1)2+(y−y1)2]1/2−[(x−x2)2+(y−y2)2]1/2=Δt12Vs 2) d1−d3=[(x−x1)2+(y−y1)2]1/2−[(x−x3)2+(y−y3)2]1/2=Δt13Vs where d1, d2, d3 are respective distances from three reception sensors to a currently input position of the digital pen, (x1, y1) is a coordinate of a first reception sensor, (x2, y2) is a coordinate of a second reception sensor, and (x3, y3) is a coordinate of a third reception sensor, Vs is a velocity of an ultrasonic wave set in advance and used for a calculation equation in the electronic device, x and y is a 2D input coordinate of the digital pen to detect, Δt12 is a difference between waveform transfer times received by the first reception sensor and the reception second sensor, and Δt13 is a difference between waveform transfer times received by the first reception sensor and the third reception sensor. ### Claim 9 (depends on 1) The electronic device of claim 1, wherein correction of a 2-Dimensional (2D) input coordinate of the digital pen and a velocity of an actual waveform are calculated using a difference between transfer times of at least three cases of waveforms received by at least four reception sensors. ### Claim 10 (depends on 9) The electronic device of claim 9, wherein the correction of the input coordinate of the digital pen and the velocity of the actual waveform are calculated by comparing a first input coordinate of the digital pen calculated by first non-linear second degree simultaneous equations with a second input coordinate of the digital pen calculated by second non-linear second degree simultaneous equations, wherein the first non-linear second degree simultaneous equations comprise: 1) d1−d2=[(x−x1)2+(y−y1)2]1/2−[(x−x2)2+(y−y2)2]1/2=Δt12Vs 2) d1−d3=[(x−x1)2+(y−y1)2]1/2−[(x−x3)2+(y−y3)2]1/2=Δt13Vs where d1, d2, d3 are respective distances from three reception sensors to a currently input position of the digital pen, (xl, yl) is a coordinate of a first reception sensor, (x2, y2) is a coordinate of a second reception sensor, and (x3, y3) is a coordinate of a third reception sensor, Vs is a velocity of an ultrasonic wave set in advance used for a calculation equation in the electronic device, x and y is a second input coordinate of the current digital pen to detect, Δt12 is a difference between waveform transfer times received by the first reception sensor and the second reception sensor, and Δt13 is a difference between waveform transfer times received by the first reception sensor and the third reception sensor, and wherein the second non-linear second degree simultaneous equations comprise: 1) d1−d2=[(x−x1)2+(y−y1)2]1/2−[(x−x2)2+(y−y2)2]1/2=Δt12Vs 2) d1−d3=[(x−x1)2+(y−y1)2]1/2−[(x−x3)2+(y−y3)2]1/2=Δt14Vs where d1, d2, d4 are respective distances from three reception sensors comprising a fourth reception sensor to a currently input position of the digital pen, (x1, y1) is the coordinate of the first reception sensor, (x2, y2) is the coordinate of the second reception sensor, and (x4, y4) is a coordinate of the fourth reception sensor, Vs is the velocity of the ultrasonic wave set in advance used for the calculation equation in the electronic device, x and y is the second input coordinate of the current digital pen to detect, Δt12 is the difference between the waveform transfer times received by the first reception sensor and the second reception sensor, and Δt14 is a difference between waveform transfer times received by the first reception sensor and the fourth reception sensor. ### Claim 11 (depends on 10) The electronic device of claim 10, wherein, when the first input coordinate and the second input coordinate calculated by the first non-linear second degree simultaneous equations and the second non-linear second degree simultaneous equations, respectively, are different, the velocity of the waveform is sequentially changed such that the first input coordinate and the second input coordinate coincide, so that the input coordinate of the digital pen is corrected. ### Claim 12 A method for calculating an input coordinate of a digital pen having a waveform generator in an electronic device comprising at least three reception sensors, the method comprising: determining a difference of at least two reception times of waveforms received from the at least three reception sensors, respectively; and determining an input coordinate of the digital pen using the determined deference of at least two reception times and a velocity of the waveform set in advance. ### Claim 13 (depends on 12) The method of claim 12, wherein for the waveform generator, an ultrasonic wave generating unit is used, and for the at least three reception sensors, ultrasonic reception sensors are used. ### Claim 14 (depends on 12) The method of claim 12, wherein for the waveform generator, a vibration generating unit is used, and for the at least three reception sensors, vibration reception sensors are used. ### Claim 15 (depends on 12) The method of claim 12, further comprising: calculating a 2-Dimensional (2D) input coordinate of the digital pen using a difference between at least two cases of waveforms received by the at least three reception sensors. ### Claim 16 (depends on 15) The method of claim 15, wherein the input coordinate of the digital pen is calculated using non-linear simultaneous equations comprising: 1) d1−d2=[(x−x1)2+(y−y1)2]1/2−[(x−x2)2+(y−y2)2]1/2=Δt12Vs 2) d1−d3=[(x−x1)2+(y−y1)2]1/2−[(x−x3)2+(y−y3)2]1/2=Δt13Vs where d1, d2, d3 are respective distances from three reception sensors to a currently input position of the digital pen, (x1, y1) is a coordinate of a first reception sensor, (x2, y2) is a coordinate of a second reception sensor, and (x3, y3) is a coordinate of a third reception sensor, Vs is a velocity of an ultrasonic wave set in advance and used for a calculation equation in the electronic device, x and y is a 2D input coordinate of the digital pen to detect, Δt12is a difference between waveform transfer times received by the first reception sensor and the reception second sensor, and Δt13 is a difference between waveform transfer times received by the first reception sensor and the third reception sensor. ### Claim 17 (depends on 12) The method of claim 12, further comprising: performing correction of a 2-Dimensional (2D) input coordinate of the digital pen and calculation of a velocity of an actual waveform using a difference between transfer times of at least three cases of waveforms received by at least four reception sensors. ### Claim 18 (depends on 17) The method of claim 17, wherein the correction of the input coordinate of the digital pen and the velocity of the actual waveform are calculated by comparing a first input coordinate of the digital pen calculated by first non-linear second degree simultaneous equations with a second input coordinate of the digital pen calculated by second non-linear second degree simultaneous equations, wherein the first non-linear second degree simultaneous equations comprise: 1) d1−d2=[(x−x1)2+(y−y1)2]1/2−[(x−x2)2+(y−y2)2]1/2=Δt12Vs 2) d1−d3=[(x−x1)2+(y−y1)2]1/2−[(x−x3)2+(y−y3)2]1/2=Δt13Vs where d1, d2, d3 are respective distances from three reception sensors to a currently input position of the digital pen, (x1, y1) is a coordinate of a first reception sensor, (x2, y2) is a coordinate of a second reception sensor, and (x3, y3) is a coordinate of a third reception sensor, Vs is a velocity of an ultrasonic wave set in advance used for a calculation equation in the electronic device, x and y is a second input coordinate of the current digital pen to detect, Δt12 is a difference between waveform transfer times received by the first reception sensor and the second reception sensor, and At is a difference between waveform transfer times received by the first reception sensor and the third reception sensor, and wherein the second non-linear second degree simultaneous equations comprise: 1) d1−d2=[(x−x1)2+(y−y1)2]1/2−[(x−x2)2+(y−y2)2]1/2=Δt12Vs 2) d1−d3=[(x−x1)2+(y−y1)2]1/2−[(x−x4)2+(y−y4)2]1/2=Δt14Vs where d1, d2, d4 are respective distances from three reception sensors comprising a fourth reception sensor to a currently input position of the digital pen, (x1, y1) is the coordinate of the first reception sensor, (x2, y2) is the coordinate of the second reception sensor, and (x4, y4) is a coordinate of the fourth reception sensor, Vs is the velocity of the ultrasonic wave set in advance used for the calculation equation in the electronic device, x and y is the second input coordinate of the current digital pen to detect, Δt12 is the difference between the waveform transfer times received by the first reception sensor and the second reception sensor, and Δt14 is a difference between waveform transfer times received by the first reception sensor and the fourth reception sensor. ### Claim 19 (depends on 18) The method of claim 18, wherein, when the first input coordinate and the second input coordinate calculated by the first non-linear second degree simultaneous equations and the second non-linear second degree simultaneous equations, respectively, are different, the velocity of the waveform is sequentially changed such that the first input coordinate and the second input coordinate coincide, so that the input coordinate of the digital pen is corrected. ### Claim 20 (depends on 12) The method of claim 12, further comprising, in a case where at least four reception sensors are used: when the digital pen contacts a display screen of the electronic device, correcting an input coordinate and a velocity of the waveform; and when the digital pen is spaced apart from the display screen of the electronic device, correcting a 3-Dimensional (3D) input coordinate of the digital pen or a 3D input coordinate and the velocity of the waveform.